NEPHRIDIA AND BODY-CAVITY OF DECAPOD CBUSTACEA. 425 



p. Sep. Pericardial septum, rt. gl. Reticulate gland, s. Septum dividing 

 dorsal sac. sal. gl. Salivary gland, sh. gl. Shell-gland, sA Stomach, st.a. 

 Sternal artery, tu. Renal tube. u. I. Upper lip. 



Explanation of Figitkes. 

 All the figures were drawn with the aid of the camera lucida. 



Fig. 1. — Horizontal longitudinal section through the green gland of a larva 

 of Palsemonetes varians three or four days old, X 420. 



Fig. 2, — Transverse section of green gland of Palsemonetes at the time of 

 hatching, x 770, 



Fig, 3.— Ditto, a few hours after hatching, x 770. 



Fig. 4. — Somewhat diagrammatic transverse section through green gland 

 of old larva of Palsemonetes. x 240, 



Fig, 5. — Transverse section of young adult Palsemonetes, just behind 

 mouth. X 240, 



Fig. 6, — Transverse section of Palsemonetes larva, ten days old, through 

 the region of Maxilla II, x 240, 



Fig, 7, — Transverse section through shell-gland of a recently hatched 

 Palsemonetes larva, (The figure is combined from two sections,) X 240, 



Fig. 8, a, b, c. — Three sagittal sections of ditto, of which a is the most 

 internal, b the most external, x 240. 



Fig, 9. — Transverse section of Palsemonetes larva, about twenty-four hours 

 old, through the region of Maxilla I. x 240. 



Fig. 10. — Pal sera on serratus dissected from the dorsal surface. 



Fig, 11, — Sagittal section of larva of Palsemonetes, ten days old. x 100. 



Fig. 12. — Transverse section through anterior end of dorsal sac of young 

 adult Palsemonetes, showing the tissue from which blood-corpuscles are budded 

 off. X 240. 



Fig. 13, a, b, — Two sections through the region of cephalic aorta of a 

 Palajmonetes embryo, a represents the condition at anterior end, whilst b 

 represents the condition further back, ri = nucleus of internal layer, »" = 

 nucleus of external layer, x 240, 



Fig. 14. — Transverse sections through cephalic aorta of Palsemonetes larva, 

 within a few hours of hatching, x 240, 



A, About level of mouth, 



B. Region of paragnaths. 

 c. Ditto. 



D. Region of Maxilla I. 

 £. Region of Maxilla II. 



VOL. XXXIV, PAKT IV. NEW SER. F F 



